Chapter 7, Problem 15Q

This diagram represents the hydrogen fuel cell that was used in some of the earlier space missions.

The chemistry in the hydrogen–oxygen fuel cell can be represented by these half-reactions:

$\begin{array}{l}{\text{H}}_2(g)\to 2{\text{H}}^{+}(aq)+2e^{-}\\ \raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.{\text{O}}_2(g)+2{\text{H}}^{+}(aq)+2e^{-}\to {\text{H}}_2\text{O}(l)\end{array}$

Which half-reaction takes place at the anode and which at the cathode? Explain.